1. Field of the Invention
This invention relates to a navigation terminal device in which the map information containing location information retrieved by a server is received through a communication line and displayed on a screen, and a method of navigation.
2. Description of the Related Art
At present, various kinds of items of information are provided on an internet via a WWW (World-Wide-Web) from the world. A user can retrieve desired information by operating a terminal device connected to the web.
One of the various kinds of information services is a map information retrieval service. Through this service, the user can acquire desired map information displayed on a terminal by access to the web server containing a map data base and connected to the internet.
Specifically, when the user inputs an address, a place name, a station name or various kinds of facility and store names, the map of the inputted item and its vicinity is displayed on as image information. Therefore, with reference the map information thus displayed, the user can easily recognize where the designated station, facility, etc. is located.
Meanwhile, as a terminal device for the map information retrieval service using the above web, not only a personal computer equipped with a web connecting configuration such as a browser, but also an in-vehicle navigation system, a PDA (Personal Digital Assistants), portable telephone, etc. are used.
However, in the device having a relatively small capacity of screen such as a portable telephone, it is difficult to understand the information on the outskirts of the designated place map-displayed. This requires very troublesome excessive repetition of scrolling. The excessive repetition of scrolling affects not only the operability but waste the communication fee. Sometimes, an objection is raised by a user. This is burden also the side of the terminal.
Unlike the in-vehicle navigation system, the portable telephone does not have the function of displaying a present location or setting a route. Therefore, the present location or destination can be individually retrieved relatively easily. However, it is not easy to follow the route from the present location to the destination and its reverse. Namely, the portable telephone cannot set the user's own position. Therefore, the facility such as a station searched as a guide is set as a starting point. The destination is retrieved from the starting point by repetitive scrolling. In this case, however, the guide disappears from the screen. Therefore, even if the destination is found, it is difficult to follow the route from the guide to the destination. Therefore, the portable telephone is very poor in the operability. This is remarkable in unknown place.
On the other hand, the portable telephone developed in recent years can use the contents on Java (registered trademark) language under the use of web connection. In the service hitherto used, the side of the web starts the program and transmits the retrieval result. In this case, the burden to the navigation terminal is light whereas the that to the web server is heavy. In addition, where the high speed operation is required, comfortable operation sense and dynamic response cannot be obtained.